Module Astring.Char.Ascii

module Ascii: sig .. end
US-ASCII character support

The following functions act only on US-ASCII code points, that is on the bytes in range [0x00;0x7F]. The functions can be safely used on UTF-8 encoded strings, they will of course only deal with US-ASCII related matters.

References.




Predicates


val is_valid : char -> bool
is_valid c is true iff c is an US-ASCII character, that is a byte in the range [0x00;0x7F].
val is_digit : char -> bool
is_digit c is true iff c is an US-ASCII digit '0' ... '9', that is a byte in the range [0x30;0x39].
val is_hex_digit : char -> bool
is_hex_digit c is true iff c is an US-ASCII hexadecimal digit '0' ... '9', 'a' ... 'f', 'A' ... 'F', that is a byte in one of the ranges [0x30;0x39], [0x41;0x46], [0x61;0x66].
val is_upper : char -> bool
is_upper c is true iff c is an US-ASCII uppercase letter 'A' ... 'Z', that is a byte in the range [0x41;0x5A].
val is_lower : char -> bool
is_lower c is true iff c is an US-ASCII lowercase letter 'a' ... 'z', that is a byte in the range [0x61;0x7A].
val is_letter : char -> bool
is_letter c is is_lower c || is_upper c.
val is_alphanum : char -> bool
is_alphanum c is is_letter c || is_digit c.
val is_white : char -> bool
is_white c is true iff c is an US-ASCII white space character, that is one of space ' ' (0x20), tab '\t' (0x09), newline '\n' (0x0A), vertical tab (0x0B), form feed (0x0C), carriage return '\r' (0x0D).
val is_blank : char -> bool
is_blank c is true iff c is an US-ASCII blank character, that is either space ' ' (0x20) or tab '\t' (0x09).
val is_graphic : char -> bool
is_graphic c is true iff c is an US-ASCII graphic character that is a byte in the range [0x21;0x7E].
val is_print : char -> bool
is_print c is is_graphic c || c = ' '.
val is_control : char -> bool
is_control c is true iff c is an US-ASCII control character, that is a byte in the range [0x00;0x1F] or 0x7F.

Casing transforms


val uppercase : char -> char
uppercase c is c with US-ASCII characters 'a' to 'z' mapped to 'A' to 'Z'.
val lowercase : char -> char
lowercase c is c with US-ASCII characters 'A' to 'Z' mapped to 'a' to 'z'.

Escaping to printable US-ASCII


val escape : char -> string
escape c escapes c with:

Use Astring.String.Ascii.unescape to unescape.

val escape_char : char -> string
escape_char c is like Astring.Char.Ascii.escape except is escapes s according to OCaml's lexical conventions for characters with:

Use Astring.String.Ascii.unescape_string to unescape.